A person may be held criminally liable for the acts of another person under three circumstances:

As an accessory. Accessorial liability pursuant to § 53a-8 (a) is equivalent to liability as a principal and requires proof that the defendant had the specific mental state required for the commission of the substantive offense and acted in furtherance of that crime. See
Accessories and Accomplices, Instruction 3.1-1.

As an accessory for providing a firearm to the actor. Section 53a-8 (b) defines a different type of accessorial liability, which does not require that the person have the same intent, but requires that he or she have knowledge of the other person's intent to commit the crime with the firearm. See
Vicarious Liability for Providing a Firearm, Instruction 3.1-4.

As a coconspirator under Pinkerton. Pinkerton liability is predicated on an agreement to participate in a conspiracy, and requires proof that the substantive offense was a reasonably foreseeable product of that conspiracy. See
Vicarious Liability
under Pinkerton, Instruction 3.1-3 .

There will be cases in which the evidence may support liability under any of these theories. If a case is presented to the jury in the alternative, the court should instruct the jury that its verdict must be unanimous as to which theory supports liability.
State v. Martinez, 278 Conn. 598, 619-20 (2006). See
Unanimity, Instruction 2.11-6.